Photographic apparatus

ABSTRACT

Photographic apparatus including film-advancing structure for asymmetrically engaging a film unit and moving it into engagement with a pair of pressure-applying members. The pressure-applying members are adapted to rupture a container of processing composition located near one end of the film unit and spread the contents thereof across a photosensitive layer of the film unit to initiate formation of a visible image. The asymmetrical engagement of the film unit by the film-advancing structure may result in the film unit being slightly canted as it moves into engagement with the pressure-applying members. Advancing the canted film unit between the pressure-applying members may result in an incomplete spread of the processing composition, i.e., some portion of the photosensitive layer will not be covered by the processing composition. This condition is substantially obviated by providing the pressure-applying members with the facility to spread the processing composition across the photosensitive layer in a layer having an asymmetrical thickness, as measured in a direction transverse to the direction of movement of the film unit through the pressure-applying members.

United statesgPatent 1 1 11-11 3,854,809

DllSCOll 51' Dec. 17', 1974 PHOTOGRAPHIC APPARATUS -[57] ABSTRACT [75]Inventor: John J. Dris coll, Andover, Mass. 7 I

Photographic apparatus including film-advancing U 1 Asslgne? 322: ""F"Cambndge structure for asymmetrically engaging'a film unit and y movingit into engagement with a pairof pressure- Filed: July 2, 1973 applyingmembers. The pressure-applying members 'are adapted to rupture acontainer of processing com- 1 position located near one end of the filmunit and 1 Related U.S. Application Data spread the contents thereofacross a photosensitive [63] continuationqmpan f 229,669, t 24, layer ofthe film unit to initiate'formation of a visible v 1972, abandoned,image, The asymmetrical engagement of the film unit 1 I by'thefilm-advancing structure may result in the film [521 U.S. c1. 354/86unit being s g y canted as it moves into, engagement 51 1111.0. .G03b 1750 with the P pp y members Advancing the [58] Field of Search, 95/89 R,89 L, 89 A, 13; canted film unit betweenthe p pp y 354/83 85 86 302betsmay result in an incomplete spread of the pro- 2 1 i cessingcomposition, ile some portion of the photo- [56] R f e Cit d sensitivelayer will not be covered by the processing UNITED T E P Tgompositzilon. "{jhis condition 'ils'substantiglly obvriiatid jj I I ,yprovi ing t e pressure-app ying-mem ers-wit t e l3/1963 Ha rn1lton.......: 95/13 facility spreadnthe processing p io across [1967.Murphy 95 13 3,4 6,427 12/1968 Murphy 95/13 x F phoFosensmle layer "1 1m 3,537,371 11/1970' Finelli 95/13 thlckness, as measured a drectwntransverse 3,625,130 12/1971 Van Allen et al.... 95/89 L x 0 thedirection of movement of fi m unit thr ugh 3,673,938 7/1972 Michatek 5111.... 95/13 th p ssu -apply g rs- 3,739,701 6/1973 12 11611612111.141195/13 3,742,834 7/1973 Thoenen 95/ l 3 Primary Examiner -Fred L. BraunAttorney, Agent, o r Firm Ailired E. Corrigan 1 35 Clain1s,'7 Drawi ngFigures V VPATENIEUEECII new sum 1 er 3 image within-the I ing the filmunit toa-viewing'station'. i

r PnoTooRAPuIC- APPARATUS- :Ross REFERENCE TO RELATE APPLICATION Thisapplication is in part a continuation of my copendingtapplication Ser.No. -299,669,"filedOct. 24,

1972 now abandoned.

BAcxoRouND oF THE NvENTloN 1. Field of the Invention This inventionrelates to photographic apparatus of the type adapt-edfto spread'aprocessing'composition across an exposed photosensitive layer; 3

' 2. Description of thePrior Art Photographic apparatus of theself-developing type are well known-in the art and generally includefilm advancing means for engaging and moving an exposed film unit out ofits exposureposition and into engage ment with a pair ofpressure-applying members, e.g.,

skewed a few degrees as it enters the bite" of the pres sure-applyingmeans, the processingvcompositioncontained within the'pod would notonlyspread from the front of the film .unit to the rear but it,thecomposition, would also have a tendency to move laterally toward oneside of the'film unit because of the angle "between-thepressure-applyingmeans and the discharge end(s) of the pod(s). Movementof the processing composition toward .the' one side. of the film unitand away from the other side thereof during front to rear spreadingmayresult in a spread which does not cover the rear corner of the otherside of the film unit. This problem .is substantially obviatedbyspreading the process composition on the other side of the film un'itin.a thinner layer than on the one side thereby spreading the availableprocessing composition on the other'sidelover a greater area before-itbecomes depleted; This is accomplished, in a preferred embodiment, byproviding the rollers. The film unit includes, a pod o'rcontainer, of

processing composition, e.g.,- liquid, havinga sealed,

rearwardly facing discharge end which is parallel with and adjacent to aleadingend of the film unit. The rollers are adapted to engage the.leading end of the film unit and the pod to generate suffi'cientpressure within the processing composition to rupture thefseal andspread the contentsthereof across a photosensitive layer of the filmunittoinitiate formation of a visible film unit while simultaneouslyadvanc- Generally, the film-advancing" means is constructed andpositioned such that the film unit is not canted 'a's it moves intoengagement with the bite of thejrollers, i.e.,-the,leading end of thefilmunit is generally parallel with the axes of the rollerstherebyenablingthe rollers to maximize the spread of the processingcomposition across thephotosensitive layer of the film unit. Obvi-'ously, this criterion 'severelyrestricts' the jdesi'gners choice andarrangement of the film-advancingmeans.

Therefore, there is a needvtfor a camera of the selfdevelopingtyp'e'wherein the film unitmaybe advanced in a canted orientationbetween-the pressure-applyingmembers without adversely affecting thequality of the spread ofprocessing composition across thephotosensitive. layer;

SUMMARY OF THE INVENTION out of its'exposure position and intoengagement with the pressure-applyingmeans. Ordinarily, orienting thefilm unit in a skewed manner prior to its'entry between thepressure-applying means willincrease the possibility that the contentsof the pod of processing composition located adjacent the leading end ofthe exposed film unit will not, be spread over the entire areaof thefilm units photosensitive layer thereby resulting in a portion ofthephotographed scene not being processed into a visible image. Forexample, if the film unit were camera with pressure-applying means,e.g., a pair of rollers, which are adapted to spread the processingcomposition ac'ross the film unit ina layer having an asymmetricalthickness as measured transversely of the film .unit with the minimumdepth of the layer being located on that side of the film 'unitwhere'incomplete coverage of the photosensitive area by the compositionis most likely to-occur."

One of the rollers, preferably the bottom roller, has

a generally symmetrical longitudinalcross section including oppositeendportionswhich are adapted to engage longitudinally extending binding.elements of a film unit. The other roller, i.e., the top roller,includes collars at each end thereof which are adapted to engage theends of the bottom roller for-providing a gap'of predeterminedminimumdepth therebetween to facilitate entry of the-fiIm unit. The top rolleralso includes an intermediate film unit engaging portion having a lengthslightly less than the lateral'distance betweenthe binding elements andfilm unit engaging endlportions'located between each end of theintermediate portion and the collars. The aforementioned end portions ofthe top roller areadapted to cooperate with the opposite end portions ofthe bottomroller to engage the I binding elements ofthe film' unit as itpasses therebetween to define the'depth of the layer of vprocessingcomposition to be spread across the photosensitive layer.

As stated above, if the exposed film unit enters the bite of the rollersin a canted orientation, a portion of the photosensitive layer ofthefilrn unit may not be covered by the layer of processing composition.To provide for this contingency, one-of the end portions of the toproller is provided with a smaller diameter than the other end portion ofthe top roller, thus resulting in the longitudinally extendingasymmetrically configured gap between thekrollers when a film. unit ispassing therebetween. Also, the end portion of the top roller having thereduced diameter is located on the side of the roller assembly whichfirst receives a portion of the leadingend of the canted or skewedfilmunit because, it is usually the rear comer of the film unit locatedon the same side of thelongitudinal axis of the film unit as 1 thatportion which .first enters the bite of the rollers where theaforementioned incomplete coverage of the photosensitive layer willoccur. The asymmetrically configured gap between the rollers, which is aresult of reducing the diameter of one of the end portions of the toproller, provides a structure wherein the depth of the layer ofprocessing composition is thinner on that side of the film unit whichfirst enters the bite of the rollers than on the other side of the filmunit, i.e., the rollers spread the processing composition across thephotosensitive layer of the film unit in a layer having an asymmetricalthickness, as measured in a direction transverse to the direction ofmovement of the film unit relative to the rollers. By spreading theprocessing composition in a thinner layer on the side of the film unitwhere the incomplete coverage is most likely to occur, the processingcomposition originally available on that side of the film unit is spreadover a greater area of the photosensitive layer'before the compositionbecomes depleted. 1

In an alternative embodiment, the pressure-applying means preferablyinclude a pair of rollers which define a gap through which an exposedfilm unit is adapted to be moved, and a torsion spring the'opposite endsof which are adapted to engage opposite ends of one of,

end, thereby asymmetrically loading the roller. When a film unit islocated between the rollers, the asymmetrical loading produces anelongated asymmetrically configured gap between the rollers with thedepth of the gap toward the end having the greaterforce being less thanthat at the other end, to producea layer of processing compositionhavingan asymmetrical thickness. The end of the roller having the greatestbiasing force is adapted to spread the processing composition ina-thinner layer across that side of the film unit where theaforementioned incomplete spread is most likely to occur, therebyinsuring complete coverage of the photosensitive area of the film unit.

cally configured gap for spreading a processing composition across aphotosensitive layerof an exposed film unit as it is being advancedtherethrough.

Another object of the invention is to provide pressure-applying meansincluding a first member having a longitudinally extending,asymmetrically configured surface defining-one portion of a gap and asecond member having a longitudinally extending, symmetricallyconfigured portion defining a second portion of a gap. v

Another object of the invention is to asymmetrically bias at least oneof a pair of pressure-applying members to provide a spread of processingcomposition of nonuniformthickness. t

Still another object of the invention is to provide pho asymmetricallyspreading a processing composition across the film unit in a layer ofnon-uniform thickness.

Still another object of the invention is to provide a spreading assemblyfor spreading a processing composition across substantially the entirephotosensitive area of an exposed film'unit whichwas originally movedinto engagement with the spreading assembly in a skewed or possessingthe construction, combination of elements In still another embodiment,the pressure-applying means preferably include a pair of juxtaposedrollers which cooperate with each other to define a gap having anasymmetrical configuration. One of the rollers, preferably the upperroller, has asubstantial'ly uniform diameter throughout a major portionthereof while the other roller has a substantially candlepin"configuration, i.e., its diameter gradually decreases from a maximumdiameter intermediate its ends to a minimum diameter at or near itsopposite ends. The configuration of the other roller is alsoasymmetrical in that its major diameter is closer to one end of theroller than the other end, and more specifically, is located closer tothe end of the roller assembly which first receives a leading endportion of an exposed film unit. As in the embodiments previouslydescribed, offsetting the maxi- Another object of the invention is toprovide a camera of the self-developing type with pressure-applyingmeans having a longitudinally extending, asymmetriand arrangement ofparts which are exemplified in the following detailed disclosure, andthe. scope of the application of which will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS Fora fuller understanding of thenature and objects of the invention, reference should be had to. thefollowing detailed description taken in connection with the accompanyingdrawings whereini FIG. 1 is a perspective view, partly insection, ofphotographic apparatus embodying the instant invention;

FIG. 4' is a diagrammatic end view of a film unit passing between thespreadrollersof the assembly shown in FIG-2;

FIG. 5 is a diagrammatic end view of a film unit passing between a pairof asymmetricallybiased spread rollers; and a FIG. 6 is a diagrammaticend view of a film unit passing between a pair of spread rollers of analternative embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION Reference is now made to FIG. 1 ofthe drawings wherein is shown photographic apparatus in the form andshutter assembly. 24, a photocell 26 and an expoof the support member 94with a generally U-shaped central portion lthereof extending around alip 102 shown in FIG. 1 and a compact folded position, as is v morefully described in US. Pat. No .',3,678,83l.

Exposure chamber 12 is adapted to receive a film cassette 32 having anexposureaperture 34 in a forward wall 36, a resilient member 37extending part way across an exit opening 38 in one end wall to preventthe passage of more than one film unit at a time therethrough and anelongated opening 40 in wall '36 which extends to the rear (to the left)of the cassette and part way down the rear endwall of the cassette.Positioned within cassette 32 are a plurality of film units 42 (see FIG.3) which may .be of the type shown in US. Pat. No. 3,415,644. Each filmunit 42 includes a leading end 44 having a. container or. pod 46containing a processingcomposition '47 attached thereto, superposedimage-receiving and photosensitive'layers positioned in alignment withopening 38, and a trailing end 50.

Camera further includes a motor 52.which may be powered by a batterylocatedwithin cassette 32, a gear train 54 for operating variouscomponents of the camera including film-advancing means 56 having acantiformedon 'the support member and seated against a' supportingsurface 104 of that member. When the spring 96 is positioned on thesupport member 94 and f the support member connecteclto the bracket80 asindicated, an elongated projection 106 depending from the bracketsflange portion 92 serves to retain the dlepin configuration, but rriaybe cylindrical, has its fore relatively light in weight and of lowinertia, being leveredmounted film engaging member 58, pressureapplyingmeans including a pair of pressure-applying members or rollers 60 and62drivingly coupled to the gear train 54 via gear 64, and an elongatedmember 66 for assisting in the movement of a pivotally mountedreflecting assembly 68.

Reflecting assembly68 includes a support70 having a planar mirror 72mounted on one side thereof and an echelon type reflecting surface 74 onthe other side. As is morefully described in U.S. Pat. No. 3,678,831,reflecting assembly 68 is adapted to be pivoted'between an exposureposition adjacent a mirror 76 located on housing section 18 whereinlight from lens 24 is reflected-by mirror 72 to expose the uppermostfilm unit closely adjacent cassette 32 wherein echelon'surface rotatablymountedon ashaft 108 by a pair of ball bearing assemblies 110. Oppositeends of theshaft 108 extend through elongated slots 112 and 114 providedin the ears 82 and 84 of the bracket 80. Flattened ends 116 and 118 ofthe torsion spring 96 seat in appropriately positioned annular recesses120 of the shaft 108 so that the force of that spring continually urgesthe roller 60 towards itsupwardmost position within the slots 112 and114 as viewed-in FIG. 2. It will be noted that the support member 94 isconfigured with a pair of cutouts 121 to accommodateinitial loading ofthe spring 96 and subsequent displacement of its flattened ends -1 l6and l 18 responsive to translatory movement of the shaft 108 along thebrackets slots 112 and 114.

Extensions 122 of the roller 62 are respectively journaled to thebracket .80 by ball bearing'assemblies 124 mounted in the brackets cars82 and 84. Provided on the roller 62 are a pair of spaced apart annularcollars 126 against which the roller 60 is initially seated under 74cooperates with lens 24, mirror 76 and viewing de- As indicated, thepresent invention isparticularly directed to certain aspects of thecamers spreading assembly, the nature of which may best be understoodbynow referring to FIG. 2 of the drawings. As shown therein, the assemblycomprises a spread roll bracket 80 preferably formed from a unitarypiece 'of sheet metal such as a stainless or carbon steelj Bracket 80includes a pair of upturned ears 82 and 84 joined together by a centralportion 86 comprising a support 88 and spaced apart substantiallyparallel flange portions 90 and 92. A rigid structural support member-94is configured to seat against the support 88 intermediate the ears 82and 84 and nested between the flange portions 90 and 92 of thebracket80. A pair of rivets 95 serve to secure the support member 94 tothe bracket'80.. A specially configured'torsion spring 96 rests intracks 98 the force of the torsion spring 96. These collars 126, de-

termine a controlled minimum gap between thesheetcontacting fa'cingsurfaces 128and 1300f the rollers .60 and 62 which facilitates theinitial introduction of a film unit therebetween. As the film unit 42 isintroduced between the rollers and v62 (see FIG. 4) it effects adisplacement of the roller 60 away from the roller 62 against theforceexerted on the roller 60 by the torsion spring 96. As the exposed filmunit 42 is advanced between the rollers 60 and 62,'the compressive forceexerted thereon by same effects a spreading of the processirigcomposition from ,pod 46 in a layer across the photosensitive layer ofthe film unit. Preferably, the roller 62 is provided with a'pairofspaced apart annular recesses 132 strategically positioned as showntoreceive selected portions of specially configured longitudin a1 edgebindings 134 of the film unit 42 in order to preclude the red-framingeffect'in accordance with the teachings of US. Pat. No. 3,647,441 byAlbert J. Bachelder entitled PHOTOGRAPHIC APPARATUS AND METHOD,issued'on Mar. 7, 1972.

In this unique arrangement, any frictional forces in the roller 60 shaft108 assembly resulting from twisting or cocking of the bearingassemblies l1 0fare absorbed by the shaft 108 which is basically a'nonrotating component. Thus, such frictional forces are .therebyreducing the load on that energy source. Most significantly, frictionalforces of the roller assembly have been minimized by providing anarrangement wherein there is a non-rotating contact between the ends 116and 118 of spring 96 and the shaft 108.

OPERATION After the photographer has focused the scene through theviewfinder 30, button 28 is depressed to initiate an exposure cycle.Subsequent to actuation of button 28, exposure chamber 12 is madelighttight by closing shutter 24 and the viewfinders entrance pupill1 1. Motor 52 is energized to move reflecting assembly 68 to the up orexposure position. Motor 52 is then stopped and the shutter opened andclosed to expose the forwardmost film unit 42 in cassette 32. Motor 52is again' started to drive gear train 54 to move member 8 I I right sidethereby resulting in the composition on the left side being depletedbefore the corner area 153 of the film unit has been covered by theprocessing com- 66 to the left, as viewed in FIG. 1, thereby returningrefleeting assembly 68 to the viewing position and to actuatefilm-advancing means 56. Actuation of the filmadvancing means moves thefilm engaging member 58 into contact with the trailing edge 50 of filmunit 42 to move the film unit out of itsexposure position and into thebite of the rotating rollers 60 and 62 via exit opening 38 in cassette32. It should be noted that the film engagingmember 56 engages the filmunit on one side of its'longitudinal axis, indicated as 115 in FIG. 3.En gaging and moving a film unit in this manner may result in the filmunit being canted as it is about to enter the bite of rollers 60 and 62as shown in FIG. 3. Canting of the film unit 42 is possible becauseusually its width'is slightly less than the width of the interior ofcassette 32.

Should the film unit enter the bite of rollers 60 and 62 in a cantedcondition, a spread pattern similar to that position. Obviously, thistype of a spread will not produce a visible image in area 153.

The present invention substantially obviates this problem byconstructing thespreading assembly such that it spreads the processingcomposition in a thinner layer on the left side of the film'slongitudinal axis 115 than on the right thereby increasing the area thatcan be covered by the processing composition on the left side.Specifically, this is accomplished by providing the left end portion 127of roller 62 with a diameter less than that of intermediate section 130(asbest seen in FIG. 2a) and right end portion 129, the latter twohaving substantially the same diameters. As shown in FIG. 7

and configuration between the sheet-contacting surfaces 128 and 130 ofrollers 60 and 62. Providing the left end portion 127 of roller 62 witha smaller diameter than that of right end portion 129 results in theleft hand portion as viewed in FIG. 4) of sheet-contacting surface 1'30extending further into opening 48 in film unit 42 than the'right handportion of, surface 130, thereby providing a gap between surfaces 128and 130 having a longitudinally extending, asymmetrical configurationfor spreadingthe processing composition in a layer having anasymmetrical thickness as measured shown by the lines 140, 142, 144,146, 148, 150 and i 152 in FIG. 3 may be produced. These lines representprogressive stages of the advancing edge of the processing compositionduring spreading of thecomposition.

For example, where pod 46 is comprised'of three segments, as shown inFIG. 3, initial rupturing of the pod 46 by rollers 60 and 62 presents anadvancing wave front as shown at 140. As the film unit continues to movethrough the rollers 60 and 62 the major portion of the wave frontprogressively flattens out while the created as a result of the acuteangle between a line containing the discharge end 49 of pod 46, which isperpendicular to the longitudinal axis 115, and a plane containing thelongitudinal axes of the rollers. Lateral movement of the'processingcomposition to the right may result in the left. side of the wavereceding relative to the remainder of the wave front until you reach acondition as shown at 152 where substantially the entire photosensitivearea of the film unit has been covered with processing compositionexcept for area 153. In other words, it appears that the amount ofcomposition originally providedfor covering the left half of the filmunit is gradually reduced by the movement of the composition from theleft side of the'film unit to the transversely of the direction ofmovement of the film unit relativeto the rollers. Stated'another way,reducing the diameter of left end portion 127 allows the left end ofroller to move closer to-the left end of roller 62, thereby resulting inroller 60 being slightly canted off its horizontal axis relative to thehorizontal axis 131 of top roller 62 when a film unit is passing betweenthe rollers. In practice, it has been found that where the diameter ofsheet-contactingportion 130 of roller 62 has adiameter of approximately.250 inches, a diameter of approximately .2496 inches for left end'portion 127 is sufficient to substantially obviate the aforementioned 1,45 problem of incomplete coverage, of the film unit's pholeft side ofthe wave trails behind, as shown from 146 I tosensitive layer by theprocessing composition. While the present invention, including all ofits embodiments, provides for spreading the processing composition in alayer of non-uniform thickness, it should be realized that the depth orthickness of the layer of composition on each side of the filmunits-longitudinal axis within the limits necessary to initiatedevelopment and form the desired photographic image. For example, in afilm unit of the type described, the thickness-of the layer ofprocessing composition may be between .002 and .003 inches. Thinning outthe thickness of the layer of processing composition on the left side ofthe film unit by approximately .0001 inch relative to the right side ofthe film unit is generally sufficient to obtain complete coverage ofarea 153.

Reference is now made to FIG. 5 wherein an alternative embodiment of theinvention is depicted. In this embodiment roller 62' is similar toroller 62 except that the left side of shaft 108 (as viewed in FIG. 2)with a spring load of 4.75 lbs. and the right side of the'shaft withaload of 3.75 lbs. provides a spread which com-,

pletely covers a picture area (defined by opening 48) of approximately3.1 inches square when the pod contains 800 milligrams of processingcomposition. The asymmetrical biasing of shaft 108 and roller 60 isaccomplished' by originally forming the end 1.16 of spring 96-at anangle relative to end 118, as shown at 116' in FIG. 2, such that afterassembly of the spreader assembly, the end of spring96 having end 116located in position 116' will be under greater compression than theopposite end of the spring, thereby providing a greater load on the endof shaft 108 which is closest to the drive side of thespreader assembly,i.e., the left side as viewed in FIGS. 2-6. As best seen in FIG. 5, whena film unit enters the bite of rollers 60 and 62, roller 60 ismoved awayfrom roller 62'. As the film unit enters between the rollers, the gaptherebetween changes to an asymmetrical configuration with the minimumdepth of the gap being on the left side of the roller assembly.Accordingly, when the rollers rupture pod 46, the processing composition47 which was contained in the pod closest to the left side'of the filmunit is spread in a thinner layer across the photosensitive area,therebyenabling the composition to be spread over a greater area, i.e.,the entire area defined by opening 48.

Reference is now made to FIG. 6 wherein stillanother embodiment of theinventionis illustrated. In this embodiment thespreading assemblyincludes a top roller 62' and the bottom roller 60' mounted for'rotation about parallel axes 131 and-13s. Roller 60 is adaptedtocooperate with roller 62 to' define a longitudinally extending (fromend-to-end of therollers) asymmetrically configured gap therebetweenwhen a film unit is located between the rollerspspecifically, roller 60is provided with a candlepin configuration having a major diameterat 160which gradually decreases to similar minor diameters near its ends 162and 164. It should be noted that the major diameter 160 is locatedoffcenter, 'i.e., it is closer to end 162 than end 164,

thereby decreasing the thickness of the processing 45 composition 47 onthe left side of the spreading assembly relative to the right side. Asin the previous embodimerits, rollers 60 and 62'- cooperate with eachother to spread the processing compositionv across a photosensitivelayer of the film unit in a layer having an asymmetrical thickness, asmeasured in a directiontransverse to the direction of movement of thefilmrelative to the rollers, with the minimum thickness of the layerbeing located on that side of bite of the rollers.

Since certain changes may, be made in the above apparatus withoutdeparting from the scope of the invention herein involved, it isintended that all matter conthe film which first enters the of theexposed film unit in a layer having an asymmetrical thickness, asmeasured in a plane transverse'to the direction of movement of the filmunit relative to .said pressure-applying means, said pressure-applyingmeans including means defining a longitudinally extending,-asymmetrically configuredgap when the film unit is being advancedtherebetwee'n, said gap tapering from' a maximum thickness at one endtoa minimum thickness at a point more than halfway toward its oppositeend be engaged by a leading edge of the exposed 'filmunit before or atthe time that said one'end ofsaid gap is engaged by the leading end ofthe exposed film unit.

3. Photographic apparatus for spreading a processing composition acrossaphotosensitive layer. of an exposed film unit comprising:

pressure-applying means adapted to engage opposite sides of an exposedfilm unit for spreading a pro cessing composition across aphotosensitive layer of the exposed film unit in a layer having anasymmetrical thickness, as measured in a plane transverse to thedirection of movement of the film unit relative to saidpressure-applying means, said pressure-applying means including meansdefining a longitudinally extending, asymmetrically configured gap whenthe film unit is being advanced therebetween, said gap tapering from amaximum thickness at one end to a minimum thickness at a location lessthan one half of the distancebetween opposite ends of said gap. 4.Photographic apparatus as defined in claim 3 wherein said one end ofsaid gap is adapted to be engaged'by a leading edge of .the exposedfilmunit at or t after the time that the'oppositeendof saidgap isengaged by the leading end of the film unit.

5. Photographic apparatus as defined claim- 4 wherein saidpressure-applying means includes first and second rollers, said firstroller having'film unit engaging surfaces including first and secondend'portions and an intermediate portion having a maximum diameternonuniformly spaced .from said first and second end portions.

6. Photographic apparatus as defined claim 5 wherein said second rollerincludes film unit engaging portionshavi-ng similar diameters. A

Photographic apparatus as defined in claim 6 wherein said film unitengaging portions of said second roller include an intermediate'po'rtionand first and second end portions, said second roller further includinga recess located adjacent each end of said intermediate portion of saidsecond roller and said first and second end portions of said'secondroller.-

8.-Photographic apparatus as definedin claim 7 further including meansfor establishing a predetermined minimum spacing between said first andsecond rollers.

ingcomposition across a photosensitive layer of an exposed film unitcomprising:

' pressure-applying means including a first roller-having alongitudinally extending symmetrically configured film engaging portionand a second roller having film unit engaging surfaces including firstand second end portions, said first and secondrollers being adapted toengage opposite sides of an exposed film unit for spreading a processingcomposition across a photosensitive layer of the exposed film unit in alayer having an asymmetrical thickness, as measured in a planetransverse to the direction of movement of the film unit relative tosaid pressure-applying means, said pressureapplying means defining alongitudinally extending, asymmetrically configured gap when the filmunit is being advanced therebetween, said .gap tapering from a maximumthickness at one end to a minimum thickness at a point'more than halfwaytoward its opposite end, said opposite end of said gap being positionedto be engaged by a leading edge of the exposed film unit before or atthe time that said one end of said gap is engaged by the leading end ofthe exposed film unit, said first end portion being located near saidopposite end of said gap and having a diameter less than that of saidsecond end portionl l1. Photographic apparatus as defined in claimwherein said second roller includes an intermediate film unit engagingportion located between said first and second end portions, saidintermediate film unit engagingportion having a diameter substantiallythe same assaid second-end portion. a

l2. Photographic apparatus as defined in claim 11 wherein said secondroller .further includes a recess located adjacent each end of saidintermediate film unit exposed film unit therebetween.

l4. Photographic apparatus as defined in claim 10 further includingmeans for resiliently biasing one of said said first and second rollerstoward the other.

15. Photographic apparatus for spreading a process: 7

ing composition'in a layer between a pair of elements,

at least one of which forms part of a film unit, said apparatuscomprising:

pressure-applying means including first and second means adapted todefine an elongated gap throughwhich a film unit is adapted to be moved;

means for mounting said first and second means for relative movementtoward and away from each other; and I means for applying anasymmetrical biasing force to one of said first and second meansduringspreading of a processing composition across a photosensitive layer ofthe film unit, whereby said first and second means spreads theprocessing composition in a layer of non-uniform thickness.

16. Photographic apparatus as defined in claim 15 wherein said firstmeans is a roller assembly having opposite end portions and said biasingmeans is mounted for engagement with at least one of said end portions.

18. Photographic apparatus as defined inclaim 17 wherein said biasingmeans. is a torsion spring having opposite ends adapted to engagesaidend portions of said roller assembly.

l9. Photographic apparatus as-defined in claim 18 wherein said oppositeend portions of said roller assembly comprise substantiallynon-rotatablepor tions of said roller assembly, whereby frictionallosses between said opposite ends of said torsion spring and saidopposite end portions of said rollerassembly are substantiallyeliminated. l

20. Photographic apparatus comprising:

means for supporting a film unit having a longitudinal axis in positionfor exposure;'

means for engaging the film unit on one side of the longitudinal axisand moving the film unit out of the exposure position subsequent toexposure; and

dinally extending, asymmetrically configured gap when the film unit isbeing advanced therebetween,

.said gap tapering from a maximum thickness at one end to a minimumthickness at a pointmore than halfway toward its opposite end.

21. Photographic apparatus as-defined in claim'20 wherein saidpressure-applying means includes first and second rollers.

22. Photographic apparatus as defined inclaim 21 wherein said firstroller includes a film unit engaging portion having a substantiallylongitudinally extending symmetrical configuration and said secondroller includes film unit engaging portions of different diameters.

23. Photographic apparatusas defined in claim 22 further including meansfor biasingone of said first and second rollers toward the other. a l

24. Photographic apparatus as defined in claim 21 diameter locatedcloser to one end of said film unit engaging portion than to itsopposite end and said second roller includes film unit engaging portionsof substantially identical diameters. l

25. Photographic apparatus as defined'in claim 24 further includingmeans for biasing one of said first and second rollers toward the other.

26. Photographic apparatus comprising: means for supporting a film unithaving a longitudinal axis in position for exposure; means for engagingthe film unit on oneside of the longitudinal axis and moving the filmunit out of the exposure position subsequent to exposure;pressure-applying means mounted in position to receive'the exposed filmunit as it moves away from the exposure position, said pressure-applyingmeans including first and second means adapted to define an elongatedgap through which the film unit is adapted to be moved;

means for mounting said first and second means for relative movementtoward and away from each other; and

means for applying an asymmetrically biasing force to one of said firstand second means to spread a processing composition across aphotosensitive layer of the film unit, said asymmetrical biasing forcebeing greatest on the longitudinal side of the film unit engaged by saidmeans for engaging, whereby said pressure-applying means spreads theprocessing composition ina layer of non-uniform thickness.

27. Photographic apparatus as defined in claim 26 wherein said firstmeans is a roller assembly having opposite end portions and said biasingmeans is mounted for engagement with at least one of said end portions.

1 said roller assembly, whereby frictional losses between saidoppositeend of said torsion spring and said opposite end portions of said rollerassembly are substan tially eliminated.

31. Photographic apparatus for use with a film unit having leading andtrailing edges. interconnected by spaced side edges and a container ofprocessing composition located adjacent the leading edge which isadapted to be ruptured prior to spreading the processing compositionacross a photosensitive, layer of the film unit and toward the trailingedge, comprising:

unit.

means for locating the film unit in position for exposure; meansforengaging the film unit ing movement to the film unit as it isadvanced out of the exposure position, subsequent to exposure; andpressure-applying means for spreading the processing composition acrossthe photosensitive layerin'a layer having an asymmetrical thickness asmeasured in a plane transverse to the direction of movement of theexposed film unit relative to said pressure-applying means, saidpressure-applying means including means adapted to define alongitudinally extending, asymmetrically configured gap when the filmunit is being advanced therethrough.

32. Photographic apparatus as defined in claim 31 wherein said gaptapers from a maximum depth near one end to a minimum depth near itsopposite end.

33. Photographic apparatus as defined in claim 32 wherein said oppositeend of said gap is adapted to be engaged by a portion of the leadingedge of the exposed film 'unit located adjacent the oneside edge beforeor at the time that said one end of said gap is engaged by a portion ofthe leading edge of the exposed film unit located adjacent the otherside edge of the exposed film 34. Photographic apparatus as defined inclaim 31 I wherein said gap tapers from a maximum depth at one end to aminimum depth at a point more than halfway towardits opposite end.

3S. Photographic'apparatus as defined in claim 34 wherein said-oppositeend of said gap is adapted to be I at its trailing edge adjacent one ofthe side edges for applying a cant-

1. Photographic apparatus for spreading a processing composition acrossa photosensitive layer of an exposed film unit comprising:pressure-applying means adapted to engage opposite sides of an exposedfilm unit for spreading a processing composition across a photosensitivelayer of the exposed film unit in a layer having an asymmetricalthickness, as measured in a plane transverse to the direction ofmovement of the film unit relative to said pressure-applying means, saidpressure-applying means including means defining a longitudinallyextending, asymmetrically configured gap when the film unit is beingadvanced therebetween, said gap tapering from a maximum thickness at oneend to a minimum thickness at a point more than halfway toward itsopposite end.
 2. Photographic apparatus as defined in claim 1 whereinsaid opposite end of said gap is positioned to be engaged by a leadingedge of the exposed film unit before or at the time that said one end ofsaid gap is engaged by the leading end of the exposed film unit. 3.Photographic apparatus for spreading a processing composition across aphotosensitive layer of an exposed film unit comprising:pressure-applying means adapted to engage opposite sides of an exposedfilm unit for spreading a processing composition across a photosensitivelayer of the exposed film unit in a layer having an asymmetricalthickness, as measured in a plane transverse to the direction ofmovement of the film unit relative to said pressure-applying means, saidpressure-applying means including means defining a longitudinallyextending, asymmetrically configured gap when the film unit is beingadvanced therebetween, said gap tapering from a maximum thickness at oneend to a minimum thickness at a location less than one half of thedistance between opposite ends of said gap.
 4. Photographic apparatus asdefined in claim 3 wherein said one end of said gap is adapted to beengaged by a leading edge of the exposed film unit at or after the timethat the opposite end of said gap is engaged by the leading end of thefilm unit.
 5. Photographic apparatus as defined in claim 4 wherein saidpressure-applying means includes first and second rollers, said firstroller having film unit engaging surfaces including first and second endportions and an intermediate portion having a maximum diameternon-uniformly spaced from said first and second end portions. 6.Photographic apparatus as defined in claim 5 wherein said second rollerincludes film unit engaging portions having similar diameters. 7.Photographic apparatus as defined in claim 6 wherein said film unitengaging portions of said second roller include an intermediate portionand first and second end portions, said second roller further includinga recess located adjacent each end of said intermediate portion of saidsecond roller and said first and second end portions of said secondroller.
 8. Photographic apparatus as defined in claim 7 furtherincluding means for establishing a predetermined minimum spacing betweensaid first and second rollers.
 9. Photographic apparatus as defined inclaim 5 further including means for rEsiliently biasing one of saidfirst and second rollers toward the other.
 10. Photographic apparatusfor spreading a processing composition across a photosensitive layer ofan exposed film unit comprising: pressure-applying means including afirst roller having a longitudinally extending symmetrically configuredfilm engaging portion and a second roller having film unit engagingsurfaces including first and second end portions, said first and secondrollers being adapted to engage opposite sides of an exposed film unitfor spreading a processing composition across a photosensitive layer ofthe exposed film unit in a layer having an asymmetrical thickness, asmeasured in a plane transverse to the direction of movement of the filmunit relative to said pressure-applying means, said pressure-applyingmeans defining a longitudinally extending, asymmetrically configured gapwhen the film unit is being advanced therebetween, said gap taperingfrom a maximum thickness at one end to a minimum thickness at a pointmore than halfway toward its opposite end, said opposite end of said gapbeing positioned to be engaged by a leading edge of the exposed filmunit before or at the time that said one end of said gap is engaged bythe leading end of the exposed film unit, said first end portion beinglocated near said opposite end of said gap and having a diameter lessthan that of said second end portion.
 11. Photographic apparatus asdefined in claim 10 wherein said second roller includes an intermediatefilm unit engaging portion located between said first and second endportions, said intermediate film unit engaging portion having a diametersubstantially the same as said second end portion.
 12. Photographicapparatus as defined in claim 11 wherein said second roller furtherincludes a recess located adjacent each end of said intermediate filmunit engaging portion and between said first and second end portions.13. Photographic apparatus as defined in claim 12 further includingmeans for establishing a predetermined minimum spacing between saidfirst and second rollers to facilitate the entry of the leading edge ofthe exposed film unit therebetween.
 14. Photographic apparatus asdefined in claim 10 further including means for resiliently biasing oneof said said first and second rollers toward the other.
 15. Photographicapparatus for spreading a processing composition in a layer between apair of elements, at least one of which forms part of a film unit, saidapparatus comprising: pressure-applying means including first and secondmeans adapted to define an elongated gap through which a film unit isadapted to be moved; means for mounting said first and second means forrelative movement toward and away from each other; and means forapplying an asymmetrical biasing force to one of said first and secondmeans during spreading of a processing composition across aphotosensitive layer of the film unit, whereby said first and secondmeans spreads the processing composition in a layer of non-uniformthickness.
 16. Photographic apparatus as defined in claim 15 whereinsaid first means is a roller assembly having opposite end portions andsaid biasing means is mounted for engagement with at least one of saidend portions.
 17. Photographic apparatus as defined in claim 16 whereinsaid biasing means is mounted for engagement with both of said endportions.
 18. Photographic apparatus as defined in claim 17 wherein saidbiasing means is a torsion spring having opposite ends adapted to engagesaid end portions of said roller assembly.
 19. Photographic apparatus asdefined in claim 18 wherein said opposite end portions of said rollerassembly comprise substantially non-rotatable portions of said rollerassembly, whereby frictional losses between said opposite ends of saidtorsion spring and said opposite end portions of said roller assemblyare substantially eliminated.
 20. Photographic apparatus comprising:means for supportIng a film unit having a longitudinal axis in positionfor exposure; means for engaging the film unit on one side of thelongitudinal axis and moving the film unit out of the exposure positionsubsequent to exposure; and pressure-applying means adapted to engageopposite sides of the exposed film unit for spreading a processingcomposition across a photosensitive layer thereof in a layer having anasymmetrical thickness, as measured in a plane transverse to thedirection of movement of the exposed film unit relative to saidpressure-applying means, said pressure-applying means including meansdefining a longitudinally extending, asymmetrically configured gap whenthe film unit is being advanced therebetween, said gap tapering from amaximum thickness at one end to a minimum thickness at a point more thanhalfway toward its opposite end.
 21. Photographic apparatus as definedin claim 20 wherein said pressure-applying means includes first andsecond rollers.
 22. Photographic apparatus as defined in claim 21wherein said first roller includes a film unit engaging portion having asubstantially longitudinally extending symmetrical configuration andsaid second roller includes film unit engaging portions of differentdiameters.
 23. Photographic apparatus as defined in claim 22 furtherincluding means for biasing one of said first and second rollers towardthe other.
 24. Photographic apparatus as defined in claim 21 whereinsaid first roller includes a film unit engaging portion of candlepinconfiguration with its maximum diameter located closer to one end ofsaid film unit engaging portion than to its opposite end and said secondroller includes film unit engaging portions of substantially identicaldiameters.
 25. Photographic apparatus as defined in claim 24 furtherincluding means for biasing one of said first and second rollers towardthe other.
 26. Photographic apparatus comprising: means for supporting afilm unit having a longitudinal axis in position for exposure; means forengaging the film unit on one side of the longitudinal axis and movingthe film unit out of the exposure position subsequent to exposure;pressure-applying means mounted in position to receive the exposed filmunit as it moves away from the exposure position, said pressure-applyingmeans including first and second means adapted to define an elongatedgap through which the film unit is adapted to be moved; means formounting said first and second means for relative movement toward andaway from each other; and means for applying an asymmetrically biasingforce to one of said first and second means to spread a processingcomposition across a photosensitive layer of the film unit, saidasymmetrical biasing force being greatest on the longitudinal side ofthe film unit engaged by said means for engaging, whereby saidpressure-applying means spreads the processing composition in a layer ofnon-uniform thickness.
 27. Photographic apparatus as defined in claim 26wherein said first means is a roller assembly having opposite endportions and said biasing means is mounted for engagement with at leastone of said end portions.
 28. Photographic apparatus as defined in claim27 wherein said biasing means is mounted for engagement with both ofsaid end portions.
 29. Photographic apparatus as defined in claim 28wherein said biasing means is a torsion spring having opposite endsadapted to engage said end portions of said roller assembly. 30.Photographic apparatus as defined in claim 29 wherein said opposite endportions of said roller assembly comprise substantially non-rotatableportions of said roller assembly, whereby frictional losses between saidopposite end of said torsion spring and said opposite end portions ofsaid roller assembly are substantially eliminated.
 31. Photographicapparatus for use with a film unit having leading and trailing edgesinterconnected by spaced side edges and a container of processingcomposition located adjacent The leading edge which is adapted to beruptured prior to spreading the processing composition across aphotosensitive layer of the film unit and toward the trailing edge,comprising: means for locating the film unit in position for exposure;means for engaging the film unit at its trailing edge adjacent one ofthe side edges for applying a canting movement to the film unit as it isadvanced out of the exposure position, subsequent to exposure; andpressure-applying means for spreading the processing composition acrossthe photosensitive layer in a layer having an asymmetrical thickness asmeasured in a plane transverse to the direction of movement of theexposed film unit relative to said pressure-applying means, saidpressure-applying means including means adapted to define alongitudinally extending, asymmetrically configured gap when the filmunit is being advanced therethrough.
 32. Photographic apparatus asdefined in claim 31 wherein said gap tapers from a maximum depth nearone end to a minimum depth near its opposite end.
 33. Photographicapparatus as defined in claim 32 wherein said opposite end of said gapis adapted to be engaged by a portion of the leading edge of the exposedfilm unit located adjacent the one side edge before or at the time thatsaid one end of said gap is engaged by a portion of the leading edge ofthe exposed film unit located adjacent the other side edge of theexposed film unit.
 34. Photographic apparatus as defined in claim 31wherein said gap tapers from a maximum depth at one end to a minimumdepth at a point more than halfway toward its opposite end. 35.Photographic apparatus as defined in claim 34 wherein said opposite endof said gap is adapted to be engaged by a portion of the leading edge ofthe exposed film unit located adjacent the one side edge before or atthe time that a portion of the leading edge of the exposed film unitlocated adjacent the other side edge engages said one end of said gap.